Rosin-soap for paper-size.



TUNITED STATE PATENT OFricE.

nowaao n. CI-IAPPELL, or oHIoAeo, ILLINOIS.

- Rosin-source PAPER-SIZE."

srnolnxon 'riou forming part of Letters retentive. 69 4,728, ea e March 4,1902.

Application filed December 18,

To all whontit vnzty concern: I

Be it known that I, HOWARD F. CHAPPELL, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in the Manufacture of Rosin-Soap for Paper-Size, of which the following is a full, clear, and exact description.

In paper-making the body-size to render the paper non-bibulous generally consists of resinate of aluminium, a gelatinous flocculent precipitate, which is formed in the pul p bycontact of some alum compounde. g., sulfate of aluminium, Al (SO -with resinate of soda. The resinate of soda is obtained by boiling ordinary soda-ash (Na CO and common rosin together with a proper volume v of water. The rosin-soap thus derived assumes a higher position in the settling-tank because of its lesser specific gravity; but however protracted the settling practice shows a marked though minor percentage of uncombined or but partially combined rosin and soda still associated with the soap as it passes into the pulp for final reaction with the alum. In the presence of the alum such uncombined soda releases its carbonicacid gas in thepulp. This causes objectionable frothing of the charge and besides isinost apt to develop spots or blow-holes in the web at a later stage as the web passes through the calenderrolls. Uncombined rosin in the size tends to stick and tear the delicate web at the same critical stage. The present invention seeks to minimize these defects. It is based upon the discover; that by subjecting the rosinsoap-i. a, resinate of soda-410 prolonged heat without burning at a temperature markedly higher than has been the practice hitherto the nnconibined rosin and soda formerly associated with the soap almost wholly disappear. remnant of resin reacts. It becomes chemically a part of the soap and on contact with the alum in the pulp passes over into size, while the associated soda converts into sulfate and disappears in solution along with the main portion of such constituent. Common rosin is a complex body made up of several distinct analogues, and it may very well be that some of these constituents (present in minor percentage) reactwith the soda-ash vessel.

Under the stated condition of heat the 1901; Serial ll'o. 86,4 s. (No specimerisl only at the higher range of temperature distinctive of the invention. At all events, by oarefullyevaporating the resinate of soda to dryness the com pound thus obtained in desiccated state may later be redissolved and,along with the. alum, beused in forming asize that markedly lessens the frothing,spotting, and sticking commonly experienced in usual practice heretofore.

According to approved form nlathe ingre-' dients and proportions taken areas follows:

Queen- 7 Ingredien is. titty Rosin ..I .pounds.. 100 Soda-ash (Na CO .pounds. l6

WVatcr. ..gallons.. 12

so as to evaporate water excess. When the charge becomes thick and sticky, it is transferred to an open pan and there exposed to quite a hot fire, which causes the compound to harden portionwise as a flaky scale. This can be easily scraped ed and removed. The 7 scale in semidry state is exposed anew under constant raking to a low fire in a separate After some three or four hours the finished resinate is taken off and spread out in a thin layer toavoid burning. When cold, the compound sets dry and hard in condition to be easily broken up and pulverized preparatory to shipment. In lieu of separate pans the treatment might proceed ina single pan under careful stirring and control of the heat, an oil or like bath forthe pan being used, if found convenient, or, again, some suitable form of rotary drier exposed to a low flame and furnished with an internal screwstirrer could be resorted to, especially when large masses of the compound are to be dealt with. V

Precisely whatdegreo of heat will suffice to efiect the desired reaction between the minor portion of the rosin and of the soda which remain uncombined in the crude soda resinate it is difiicult to say. A hot fire at the dryingpan speeds the evaporation, but does not appear to be essential to thereaction. An excess heat would of course burn the charge. Certainly the temperature must be above 212 Fahrenheit, and, having regard for economies of time, might properly range at 230- 300 Fahrenheit. At all events the use of open pans exposed to naked fire or flames will prove quite sufficient, regardless of any niceties of temperature, proper care being taken to scrape out the scale or else to keep it well stirred as it forms, so that no scorching of the product need occur. 7

Soda resinate,desiccated by heat, as he reinbefore detailed, is found to havea much lower percentage of uncombined rosin and soda present therein than is distinctive of the older forms of such compound, and because of its improved quality serves to relieve the papermaker from the losses and delays due to frothing at the pulp-engine and to spotting am sticking at the calender-rolls.

paper-size which consists in boiling rosin in hot soda-ash solution and, after desired reaction eft'ected, evaporating water excess and finally superheating thecharge beyond 212 Fahrenheit, while stirring proceeds so that the finished resinate is derived without scorching, in desiccated state having a minimized proportion of uncombined resin and soda-ash present therein.

HOWARD F. OHAPPELL.

Eitn'esses:

JAMEs H. PEIRCE, ALBERTA ADAMICK. 

